Commonly used binders in the fabrication of commercial ultracapacitor electrodes include polyvinyledene fluoride (PVDF), ethylene-propylene, diene (EPDM), as well as other materials. The binders consist of one or more polymers, which are generally insoluble in water. Hence, organic solvent such as N-methyl pyrrolidone (NMP) is being used to dissolve these binders to fabricate electrodes. Some disadvantages of using organic solvents are that they are relatively higher in cost, they can possess negative environmental impacts, and pose disposal issues. Further, PVDF is highly unstable and tends to break down at high temperatures.
Accordingly, there is a need for water soluble binders to fabricate electrodes for ultracapacitors.